step 4—To a solution of 68 (100 mg, 0.26 mmol) in DMF (3 mL) were added 4 cyano-piperidine (32 mg, 0.29 mmol), HOBt (39 mg, 0.29 mmol), EDCI (56 mg, 0.29 mmol) and DIPEA. The reaction mixture was stirred at RT overnight then quenched with H2O and thrice extracted with EtOAc. The combined extracts were sequentially washed with H2O (3 times) and brine, dried (MgSO4), filtered and concentrated under reduced pressure to afford 126 mg (99%) of 1-[2-(2-benzyloxypyridin-3-yl)-4-tert-butyl-5-methoxybenzoyl]piperidine-4-carbonitrile (70) as a pale yellow foam.
